Robotics NXT sensors Back to Light sensor: red vs blue ball. Lab: Maze. Add mallet. Hit red ball. Homework: Postings. Develop task involving multiple sensors.

Lego sensors Include physical packaging: way to attach to other Lego pieces electrical packaging: analog to digital signal: bit pattern representing a number software for / in NXT-G: block(s) and help text

Maze Ideas? Note: can simplify maze: say only right angles. How can robot know it is done (outside of maze)?

Maze: one approach Loop Move forward a little (can set motors to glide) Check bumper. If pressed, back up and turn to the right (see next). May do this in one or two steps. Check ultrasonic mounted on the left. If >some amount, turn to left, move forward a little. THERE ARE OTHERS!

Preview: Compass sensor Calculates magnetic heading: 0 to 359 degrees Returns number Returns true/false if inside or outside specified range Absolute or relative operation…. Need to download software: Tools/Block Import and Export Wizard

Cautions Note: The compass measures the very weak earth's magnetic field. Ensure that is mounted at least 4 inches or 10 centimeters away from the NXT and motors. Why???? Also ensure that it is mounted horizontally as the heading will not be accurate if the compass isn't level. Why????

Tasks Task using ultrasonic sensor? Task using bumper (touch sensor)? Task using light? Task using compass sensor? Tasks using multiple sensors Note: just 4 ports.

Red vs Blue ball Build mallet (my word) Build stand pp 50-61 Build stand pp 62-67 OR Do your own design, perhaps use tire for stand (more stabile but need to check height) and something bigger to be detected by the ultrasound sensor. Use Mindstorms help for program. Need to pick value that distinguishes red and blue ball

Homework Postings Plan activity making use of multiple sensors Note: next week: coordinate systems, position[ing], NXT-G: variables, file system